Premature atherosclerosis is an emerging problem for patients with HIV infection who are treated with antiretroviral drugs. It is not clear whether these complications are related to HIV, the drugs, or the dyslipidemias that the drugs produce. A study has been developed to look at flow mediated dilation in patients with HIV treated with antiretroviral drugs. This technique is a surrogate for coronary artery disease that is well established, and is an assessment of endothelial function. [unreadable]